This invention relates to filled rubber compositions. In one of the aspects this invention relates to the use of aluminum phosphate as a filler for rubber compositions. In another of its aspects this invention relates to products obtained by curing rubber compositions having aluminum phosphate filler.
Carbon black has historically been the reinforcing agent of choice for rubber-based products such as tires and extruded or molded goods. Carbon black, which is produced by the thermal decomposition of oil and natural gases, greatly enhances mechanical strength and resistance to abrasion and has, in the past, been an economically attractive approach to improving the physical properties of rubber products. Increasing demand for other oil and gas derived petrochemicals, combined with the decreasing supply of oil and natural gas, has prompted the search for a replacement for carbon black as the reinforcing agent for rubber-based products.
The use of silica as a replacement for carbon black has in general brought higher cost and an at least slightly poor performance to reinforced rubber-based products. Other materials have, therefore, been tried as a replacement for carbon black that will at least perform as well as silica as a reinforcing agent for rubber-based products. Among these alternative materials it has been discovered that aluminum phosphate provides physical characteristics to rubber compositions that in some aspects are better than those obtained with silica.
Accordingly an object to this invention is to provide a novel reinforcing promoter for rubber compositions. Another object of this invention is to provide reinforced rubber: compositions exhibiting improved properties as compared to silica filled compositions. A still further object of this invention is to provide vulcanized rubber compositions containing aluminum phosphate.
Further objects, aspects, as well as several advantages of this invention will be apparent to those skilled in the art upon reading the specification and the appended claims.